Artificial hand



Dec. 17, 1940. R L DAV; 2,225,468

ARTIFICIAL HAND Filed Jan. 4, 1938 Patented Dec. 17, 1940 UNITED STATES PATENT OFFICE- ARTIFICIAL HAND Roy L. David, San Jose, Calif.

Application January 4, 1938, Serial No. 183,317 3 Claims. (01. 3-12) The artificial hand as now commonly known to the trade comprises a pair of jaws, one of which is rigidly mounted upon a frame attached to the users arm, and the'other pivotally mount- 5 ed upon the first jaw and controlled by suitable connections to the users body, the object held being grasped directly between the opposing faces of the two jaws. This formof artificial hand is far from being efficient because the varietyof 10 items which it can hold is decidedly limited, and its grasp upon such items as'it can hold is not as secure as it should be. This is so because by far the greater number of objects grasped are elongated, or have a generally cylindrical con- 15 formation, or have pressure brought to bear upon their free outer ends when in use. In such cases merely to grasp the item between two opposing jaws, with a support for its inner end portion, does not hold it firmly or rigidly enough to enable one to use or handle it with effectiveness and confidence. For instance, with such a hand the common hand-saw may be. used "successfully while resting upon the work, but its weight alone twists it in the hand when an attempt is made 25 to lift it off of the work. e

It is, therefore, the principal object of the present invention to provide an artificial hand, or hook, so constructed and arranged that it will grasp an item so securely and firmly that, to all so intents and purposes, it becomes a unitary part of the hand itself and will successfully resist displacement by any ordinary forces that may act upon its free end from any direction.

It is also an object of the invention to provide a device of the character indicated that will sesurely grasp and hold items of many different shapes and size, and one that will be economical to manufacture, light in weight, simple in form and construction, strong, durable, and highly cf- 40 ficient in its practical application.

In the drawing:

Figure l is a perspective illustration of a device embodying my invention, with parts broken away, and with the jaws opened.

45 Figure 2 is a front end elevation of the same,

with the jaws closed.

Figure 3 is a plan view of the device shown in Figure l, with the jaws closed.

Figure 4 is a side elevation of the same, with the jaws opened.

, In the particular embodiment of the invention herein disclosed I show at I and 2 two jaw members pivotally connected at 3. The member I is fixedly mounted upon a supporting frame, 55 not shown, at the end 4, and the member 2 swings in a plane at right angles to the axis of the pivot 3 adjacent said end. "Upper and lower bosses 5 and 6 are formed on said jaws to hold in place thereon an assembly of rubber bands '1, these bands serving to normally. hold said jaws in closed relation to each other. On the swingable jaw 2 is formed an upstanding part 8 provided with an eye 9L The jaw 2 is actuated against the tension of the bands I by means of any suitable connection to the eye 9, ordinarily a cable pass 10 ing back to the body of the user and acting in the direction indicated by the arrow 10, the said cable not being shown.

The vertical plane hereinafter referred to is the plane in which the part 8-4) lies, and the horizontal plane referred to is the plane in which the pivot 3 and the axis of end 4 lie, the two planes being indieatedat II and I2, respectively, Figure 2.

The jaw member I has a cylindrical portion 20. i3 projecting forwardly as shown, immediately below the horizontal plane, thence downwardly and laterally as at I4 and again upwardly and laterally in the opposite direction as at l5 to a point l6, and forming an elbow I1. Forwardly from the point It the member is formed into a hook 13 that is substantially semi-circular in transverse cross-section, the flat grasping surface l9 being uppermost, and the hook extending angularly upward at an angle of substantially 30, forty-five degrees to the horizontal.

At the base of the hook l8 and rising from its outer edgedirectly opposite the point [6 is a strap portion 20. The upper and inner edge 2] of this strap portion 20 is disposed at an angle of substantially ninety degrees to the hook I8 and forms a triangular seattherewith as indicated at 22. In the obtuse angle formed by the inner side of the strap portion 20 and the top surface ofhook I8 is provided a recess for the purpose hereinafter described, as indicated at 23.

Mounted upon the jaw member I in fixed relation thereto with its open end directed toward the seat 22, is a cupped member 24. This member 24, in the present case, is conical in form with the plane of its open end disposed at an angle to the vertical plane, and lying entirely to one side thereof, and largely above the horizontal plane.

The strap portion 29 is extended rearwardly and angularly with relation to both the vertical and horizontal planes as indicated at 25, and is connected to the cupped member 24 as at 26 by means of a short angular portion 21. The connection to the cupped member is made on the side directly opposite the attachment to the member I at 28.

On the upper edge of the strap portion is formed a slightly inwardly turned spur 29, the

v inclined forward edge of the spur and the upper edge of the strap forming an angular seat at for the purpose hereinafter described.

The jaw member 2 curves upwardly and forwardly from its pivotal mounting 3, and. also laterally as shown at 3|. The lateral curvature is such that the end 32 of the jaw will fall just within the strap portion 20 and directly over the end I6. of jaw I when the jaws are closed. This jaw member 2 terminates in a hook portion 33 that is substantially semi-circular in transverse cross-section, the grasping face 34 of this hook portion substantially paralleling the face of hook l8 when the jaws are closed. On the jaw 2 is placed a rubber sleeve as 35 to increase its gripping power and to prevent injury to, objects grasped.

Due to the arrangement of these several parts and their various conformations, the items grasped .are held by edges rather than by surfaces.

I. For instance, an item placed in the device in the position; indicated by the dotted line 36 is held" against downward or lateral movement at its-inner end by contact at two or more points with-the inner surface of cupped member 24, while its forward portion is held against downward or lateral movement by contact with the two sides of seat 22. When the jaw 2 closes down upon the item from above it lays across the same and contacts it at a point as 31 between the front and rear supports 22 and 24.

7 Since the .lowest portion of the end of jaw 2 is at 38, and since the forward seat 22 is located beyond the curved hooks l8 and 33 it follows that whenever the jaw 2 is brought down upon any item positioned as at 36 it will fall between the two end supports 22 and 24 and maximum emciencywill be obtained.

v The position indicated by line 36 is dwelt upon and also indicated in Figures 3 and 4 as well as Figure 1 because it illustrates the position most frequently used and clearly illustrates the principle involved. However, articles may be as securely held in several other positions in the same manner. If .an item is grasped in the position 39, then it rests in elbow l1 and seat 30 and is securely heldby them against downward and lateral movement. The jaw member 2 contacts theitem at a point 40 between the two points of support with the result described in connection with position 35. If the item is placed in the position 4|, then it is supported from below atpoints 42 and22 .and the jaw member 2 contacts it between these two points as at 43.

The cupped member 24 forms a socket disposed to receive one end of an item and take its end thrust, and also to supportit from below and hold it against lateral movement in either direction.

It is to be understood, of course, that while I have herein shown and described but one specific embodiment of the invention, changes in form, construction, and method of assembly and operation may be made within the scope of the appended claims.

I claim:

1. An artificial hand comprising, a jaw member, a second jaw member fulcrumed thereon, .and resilient means associated therewith to urge the jaws toward each other, the first jaw having a forwardly directed socket formed thereon adjacent the fulcrum and on one side thereof to receive one end of an item, and having a seat formed on its free end provided with diverging sides to support the forward portion of the item, and .a strap portion connecting its free end with the outer portion of said socket and having a shoulder formed on one edge, the said jaw also having an elbow formed therein in substantially opposed relation to said shoulder to cooperate therewith in supporting an item, .and the second jaw having a part disposed to extend over the area defined by the said portions of the first jaw whereby to engage an item supported thereon intermediate its points of support.

2. An artificial hand comprising, a jaw member, a second jaw member fulcrumed thereon, and resilient means associated therewith to urge the jaws toward each other, the first jaw member having a forwardly directed socket formed thereon adjacent the fulcrum to receive one end of an item, and having a seat formed on its free end provided with diverging sides to support the forward portion of the item, a member connecting the free and socket ends of the first member and laterally spaced from the intermediate portion thereof, and the second jaw member having a portion disposed to overlie the area defined by the lower jaw and connecting member whereby to engage an item supported thereon intermediate its points of support.

3. An artificial hand comprising, a jaw member, a second jaw member fulcrumed thereon, and resilient means associated therewith to urge the jaws toward each other, the first jaw member having a forwardly directed socket formed thereon adjacent the fulcrum to receive one end of an item, and having a seat formed on its free end provided with diverging sides to support the forward portion of the item, .a member con necting the free and socket ends of the first member and laterally spaced from the intermediate portion thereof, and the second jaw member having a portion disposed to overlie the area defined by the lower jaw and connecting member whereby to engage an item supported thereon.

ROY L. DAVID. 

